Classic concrete features a smooth surface or one textured using simple techniques. To give concrete a smooth finish, builders use a screed or float to wipe away excess concrete while the mixture is still wet. They may also use a bullfloat to smooth concrete over a large area. This specialty tool consists of a straight edge or squeegee positioned at the end of a long handle. To add texture and increase traction, installers often give concrete a broom finish. This helps to create light parallel lines in the surface of the concrete and is primarily used on outdoor or industrial applications.
To create an exposed aggregate finish, builders wash away the top layer of wet concrete, exposing the rocks and gravel below. For a more decorative effect, they may also press colored stone into the top of wet concrete before it dries. This serves as a popular finish for walkways and sidewalks and gives the concrete a highly textured finish.
Stains and Dyes
Stains and dyes are used to brighten up basic gray concrete finishes. They consist of powdered or liquid additives that can be mixed in with the wet concrete or applied to the finished surface. Staining can be used to give concrete a highly textured look or to mimic the look of marble and other types of stone.
Rock Salt Finishes
A rock salt finish gives concrete a decorative, yet natural finish. To create this look, contractors poor the fresh concrete, then sprinkle it with large pieces of rock salt while it's still wet. Once the concrete dries, they spray water over the surface to wash away the rock salt. This leaves a random pattern of small holes and voids in the surface of the paved area.
Etching and Stamping
Etching and stamping techniques are used to give concrete the look of brick or stone or even to create themed finishes like those found at many amusement parks. Builders may use a rubber form liner to mold the concrete into a specific shape. For a more affordable alternative, they may use a stencil or stamp to create specific patterns on textures into the wet concrete. This process may also include hand molding to add variation and give the concrete a more natural look.